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1.
付贵权  秦涛  陈小勇  雷春云  李光华 《生态学报》2021,41(24):9557-9573
根据2018-2020年澜沧江西双版纳段5次鱼类资源调查数据,结合相关文献资料,对该流域鱼类组成及物种多样性进行了分析。结果显示:澜沧江西双版纳段此次共调查到鱼类119种,隶属于11目28科79属,而历史记录鱼类共179种,隶属于12目34科106属。随着调查的不断深入,土著鱼类种数逐渐增多,但占比却逐渐下降,外来鱼类种数逐渐增多,占比也逐渐升高;本次调查到土著鱼类92种,占鱼类种数的77.31%,占比进一步下降;外来鱼类27种,占鱼类种数的22.69%,占比进一步升高。该区域鱼类优势种为云南吻孔鲃Poropuntius huangchuchieni和少鳞舟齿鱼Scaphiodonichthys acanthopterus,常见种为长臀鲃Mystacoleucus marginatus和宽额鳢Channa gachua。有《国家重点保护野生动物名录》(2021年)鱼类5种,《中国生物多样性红色名录脊椎动物卷》(2015年)受威胁鱼类8种。相对于我国其他江河,澜沧江西双版纳段有极高水平的鱼类物种多样性,其中澜沧江干流鱼类物种多样性相对于左、右岸支流较低,左岸支流鱼类多样性高于右岸,罗梭江鱼类多样性高于其他一级支流。虽然澜沧江西双版纳段鱼类物种多样性维持在较高水平,但土著鱼类占比下降趋势明显,仍面临着严重威胁,本文分析了受威胁因素,并提出了保护建议。  相似文献   

2.
3.
KEIGHERY  G. J. 《Annals of botany》1996,77(4):347-356
The Epacridaceae of Western Australia comprise 181 named speciesdistributed in 17 genera. One hundred and seventy seven species(98% of the total) and ten genera are endemic to the region.within Western Australia, all members are confined to the south,with a bimodal pattern of species diversity centred on the sandplainsand uplands around the Stirling Ranges and Mount Lesueur.Leucopogon, the largest genus, reflects this pattern, however, speciesdiversity is greatest on the south coastal sandplains. All species are woody shrubs, mostly found on neutral or acidicsandy soils. Plants of at least 120 species are killed by fire;Astrolomacontainsthe only significant number of resprouting species. Althoughsome species are in flower every month every year, autumn/winterflowering is a common feature of many members of the family.All species are biotically pollinated. Bird pollination is foundin 18 species in six genera. The remaining species are insectpollinated. Bees are the major pollinators inLeucopogon, ConostephiumandColeanthera.Moths and butterflies are important pollinators inAndersonia,Leucopogon,LysinemaandStyphelia. Flies are minor pollinators of some speciesofAndersonia, LeucopogonandMonotoca. All species studied areprotandrous and outbreeding, with onlyCosmeliabeing capableof self pollination. Fruits are fleshy inAstroloma, Brachyloma,Croninia, in certain species ofLeucopogonandStypheliaand areanimal dispersed. Other genera have dry, dehiscent fruit withgravity or wind dispersed seeds. Many species have relatively narrow distribution ranges, 90species having ranges of over 300km, 54 species have rangesof 100–300km and 37 have ranges of less than 100km (andthere are many undescribed species in this group). The conservationstatus of many species is still poorly known. Dieback diseaseis a major threat to the family, and could cause the extinctionof several species in the wild. Western Australia; Epacridaceae; phytogeography; biology; pollination; dispersal; conservation; disease  相似文献   

4.
The genus Macrophthalmothrips is redefined from a study of all the described species. One new species is described from Jamaica, five species are placed in synonymy, and a key is provided to the thirteen species now recognised. Variation in colour and antennal structure is discussed, and notes are given on the biology and distribution of the species.  相似文献   

5.
刘锡进  郭英兰 《菌物学报》1988,7(Z1):241-268
菌绒孢是一个小属,已描述过的种约50个,都是植物寄生菌,有的引致植物病害还较 严重.本文报告了我国产的21个种,其中1个是新种,4个是新组合和2个新记录,对18个种均有英文描述和附图,新种还附有拉丁文简介,各个种的地区分布也予以载述.但文中有分布地区而其后未附HMAS标本号码者多系据《中国真菌总汇》(1979)转录.从前人的描述和我们研究中看出,菌绒孢属的属级特征有:(1)产孢细胞合生,合轴式多点全壁芽茁产孢;(2)分生孢子梗壁上和分生孢子顶端和基脐,或仅基脐的孢痕疤明显而厚;(3)分生孢子梗主要从表生甸甸菌丝上作为侧枝或顶生,但有的种也兼有从子座上 簇生的;(4)菌丝多结集成菌丝绳或攀缘于叶毛上;(5)分生孢子链生,少数种也不链生. 这就清楚表明菌绒孢属与尾孢菌属和色链隔孢属(Phaeoramularia)少不同之处在于,尾孢 菌和色链隔孢属二者的分生孢子梗均成簇发生且无表生匍匐菌丝,与极其近似的假尾孢属(Pseudocercospora)不同之处在于,后者的分生孢子梗也着生于表生匍匐状菌丝和簇 生于子座上,但其分生孢子梗和分生孢子的孢痕疤却薄而不明显,因而易于区别开.虽然1974年von Arx在其《纯培养产孢真菌的属》一书中,曾把菌绒孢属作为枝孢 属(Cladosporium)的异名,但这一观点我们未予接受,其理由已在《中国色链隔孢曲(1982)一文中加以说明,这里未予重述.上述这21个种除3个种,即M. costaricensis, M, pawlownicolaM. vaginae我们未获得研究材料,仅据以前作者的报导转录外,其余18个种均系根据标本进行的.这些标本,含M. merremiae sp. nov.的模式标本在内,均贮藏于中国科学院微生物研究所真菌标本室.  相似文献   

6.

Aim

The ability of predicting which naturalized non-native species are likely to become invasive can help manage and prevent species invasions. The goal of this study is to test whether invasive angiosperm (flowering plant) species are a phylogenetically clustered subset of naturalized species at global, continental and regional scales, and to assess the relationships of phylogenetic relatedness of invasive species with climate condition (temperature and precipitation).

Location

Global.

Time period

Current.

Taxon

Angiosperms (flowering plants).

Methods

The globe is divided into 290 regions, which are grouped into seven biogeographic (continental) regions. Two phylogenetic metrics (net relatedness index and nearest taxon index), which represent different evolutionary depths, are used to quantify phylogenetic relatedness of invasive angiosperms, with respect to different tailor-made species pools. Phylogenetic relatedness of invasive angiosperms is related to climatic variables.

Results

The global assemblage of invasive angiosperm species is a strongly phylogenetically clustered subset of the species of the entire global angiosperm flora. Most invasive angiosperm assemblages are a phylogenetically clustered subset of their respective naturalized species pools, and phylogenetic clustering reflecting shallow evolutionary history is greater than that reflecting deep evolutionary history. In general, the phylogenetic relatedness of invasive species is greater in regions with lower temperature and precipitation across the world.

Main conclusions

The finding that invasive angiosperm assemblages across the globe are, in general, phylogenetically clustered subsets of their respective naturalized species pools has significant implications in biological conservation, particularly in predicting and controlling invasive species based on phylogenetic relatedness among naturalized species.  相似文献   

7.
8.
Species ofAnthostomella reported from Brunei have been re-examined and the data is summarized in this paper. Five species are accepted, four are synonyms of previously described species and one is a new species. The new speciesAnthostomella oblongata is described and illustrated and a list ofAnthostomella species known from Brunei and a key to these species are provided.  相似文献   

9.
《Mycoscience》2014,55(3):196-212
The Longibrachiatum Clade of the genus Trichoderma in Japan was examined, among which two new species and three new records are herewith reported. The new species, T. tsugarense and T. kunigamense were isolated from a bed log (cultivation of Lentinula edodes) and volcanic ash soil, respectively. These species are distinguished from closely related species by growth and morphological characteristics and in phylogenetic analysis. Additional species new to Japan were T. ghanense, T. parareesei and T. sinense. The significance of their distribution is discussed. Most species of the Longibrachiatum Clade are tropical rather than temperate in distribution. Their in vitro optimum growth tends to be >35 °C but the optimum temperature for some Japanese species was lower. Some species are endophytes of temperate plant species, some of which are endemic in Japan.  相似文献   

10.
The Palaearctic fauna of broad-winged moths (Oecophoridae with the subfamilies Oecophorinae, Pleurotinae, and Deuterogoniinae) comprises 47 genera and 329 species. The number of species rapidly increases from north to south, from 19 species in the Euro-Siberian taiga Region to 149 in the Mediterranean Region, but the Scythian steppe Region (30 species) and Sethian desert Region (49 species) have relatively poor faunas because the majority of oecophorid species are trophically associated with arboreal plants. The proper desert species are very rare among Oecophoridae moths, and the majority of species in the Sethian desert Region occur in the mountains. The number of endemic species is also greater in southern regions; it amounts for more than half of the total number of species in the Hesperian and Orthrian evergreen forest regions and in the Sethian desert Region. The faunas of European (62 species) and Far Eastern (67 species) deciduous forests comprise close numbers of species but are very different, having only 5 species in common. This fact indicates their long isolation. The Oecophoridae are represented in the Palaearctic mainly by the genera with a small number of species, except for 2 genera, Pleurota (100 species) and Promalactis (85 species). The distribution patterns of these genera are opposite: the species of Pleurota are numerous in the south of West Europe and in North Africa, their number quickly decreasing from west to east and only 2 species being present in China (Wang, 2006). The species of Promalactis are numerous in Southeast Asia, their number quickly decreasing from east to west: 3 species occur in Tibet and only 1, P. splendidella (Amsel, 1935), in Israel and Turkey.  相似文献   

11.
The Trissolcus flavipes species group is revised. A key to the species of this group is provided. In addition to the diagnostic characters, the localities are listed for each species. Eleven new species occurring in various Palaearctic areas are described. Some body structures are illustrated. The morphological characters of the new species are compared.  相似文献   

12.
中国千斤拔属植物的初步研究   总被引:7,自引:0,他引:7  
韦裕宗   《广西植物》1991,11(3):193-207
本文叙述了千斤拔属名的拉丁学名的变换和研究情况,并研究该属植物国产种的分类、地理分布及其特点。进而对该属植物的习性和苞片、花序、花和叶等诸器官演化趋势作初步探讨,并对该属6个类群之间可能的演化关系、属的起源、分布中心和迁移路线等问题提出初设想。  相似文献   

13.
14.
The species of the genus Chrysopilus, inhabiting Russia and adjacent territories, are analyzed for the first time. The structure of the genitalia is examined, and new diagnostic characters of the species are given. Some species from the boundary areas are considered in detail, since the species composition of the genus has been poorly studied there. The data on 11 species distributed in eastern Russia and Japan are given.  相似文献   

15.
A new species of macrourid, Coryphaenoides paramarshalli is described from mid to lower slope waters (l 13–160 m) off West Africa, in the area 04°S-21°N and 10°E-18°W. The species is very closely related to C. marshalli . Indeed, two of the paratypes of that species are incorporated among the paratypes of C. paramarshalli , as they are referrable to the new species. The features distinguishing the two species are discussed in conjuction with those separating C. paramarshalli from other related species.  相似文献   

16.
The coexistence and coevolution of sexual and asexual species under resource competition are explored with three models: a nongenetic ecological model, a model including single locus genetics, and a quantitative-genetic model. The basic assumption underlying all three models is that genetic differences are translated into ecological differences. Hence if sexual species are genetically more variable, they will be ecologically more variable. Under classical competition theory, this increased ecological variability can, in many cases, be an advantage to individual sexual genotypes and to the sexual species as a whole. The purpose of this paper is to determine the conditions when this advantage will outway three disadvantages of sexuality: the costs of males, of segregation, and of the additive component of recombination. All three models reach similar conclusions. Although asexuality confers an advantage, it is much less than a two-fold advantage because minor increases in the overall species niche width of the sexual species will offset the reproductive advantage of the asexual species. This occurs for two reasons. First, an increase in species niche width increases the resource base of the sexual species. Second, to the extent that the increase in niche width is due to increased differences between individuals, a reduction in intraspecific competition will result. This is not to imply that the sexual species will always win. The prime conditions that enable sexual species to stably coexist with or even supplant an asexual sister species are:
    相似文献   

17.
Snell  Terry W. 《Hydrobiologia》1989,186(1):299-310
The typological concept of rotifer species and the morphological basis of rotifer systematics is reviewed and alternatives proposed. Occasional sexuality in the cyclical parthenogenetic life cycle of monogononts permits application of the biological species concept to this group. Data from cross-mating experiments with Asplanchna, Brachionus and Epiphanes illustrate the usefulness of reproductive isolation as a criterion for species boundaries. Populations from different geographic regions are often interfertile indicating that rotifer species are genetically integrated over wide areas. The main types of isolating mechanisms operating in monogononts are reviewed. The role of behavioral reproductive isolation in maintaining species boundaries is examined. The use of a mate recognition bioassay which estimates the probability of copulation and quantifies the degree of isolation is described. Recent work of the mechanism of mate recognition is reviewed. It is concluded that the biological species concept is applicable to rotifers and that a more experimental approach to determining species boundaries is both feasible and desirable.  相似文献   

18.
The genus Hemibidessus Zimmermann, 1921 is revised. Six species are recognized in the genus. Two new species are described, H. spirodiscus sp. n. from Bolivia and H. spangleri sp. n. from Argentina. A key for identifying the species is presented. The female genitalia are thoroughly illustrated and described for the first time for any species of Bidessini. Other important diagnostic structures are also illustrated including the male genitalia. A cladistic analysis is presented for 8 species (6 ingroup and 2 outgroup species) and 13 characters. A single most parsimonious cladogram was found.  相似文献   

19.
Sex determination and evolution of unisexuality in the Conchostraca   总被引:5,自引:3,他引:2  
Clay Sassaman 《Hydrobiologia》1995,298(1-3):45-65
Field collected or laboratory-reared samples of 60 species of conchostracans (representing all extant genera) indicate that males and females are equally common in most species. Deviations from this pattern occur in four lineages.Cyzicus andLeptestheria each include at least one unisexual species; many species of Limnadiinae are either unisexual or characterized by female-biased sex ratios; and Cyclestheriidae are either unisexual or express males in the later generations of their life cycles. Laboratory studies indicate that species with sex ratios near unity are gonochoric (obligately sexual), whereas females in species with female-biased sex ratios are capable of both outcrossing and selfing modes of reproduction. Phylogenetic analysis of patterns of reproduction suggest that sexual reproduction is the primitive condition. Genetic analysis of sexual species indicate that gender is determined by one or a few genetic factors and that the male-determining allele is recessive. The inheritance of gender in androdioecious species (where females are capable of self-fertilization) is similar to that in sexual species. Androdioecy is likely to be the intermediate stage between obligately sexual reproduction and unisexuality in the Limnadiinae. The phylogenetic distribution of sex ratio variation suggests that unisexuality in Cyzicidae, Leptestheriidae, and Cyclestheriidae has arisen independently of that in the Limnadiinae and that these cases have evolved by different evolutionary pathways.  相似文献   

20.
Nine species of rust fungi (Uredinales) were found during a 1-day field study in an Acacia koa–Metrosideros polymorpha woodland in Volcanoes National Park on Big Island, Hawaii. Two species, both found on Acacia koa, are native (endemic) rusts whereas 7 species are nonnative on nonnative hosts, highlighting the high proportion of introduced species in the Hawaiian flora even in more or less natural habitats. One species, Uromyces linearis on Panicum repens, constitutes the first record of this rust for the Hawaiian archipelago, bringing the total to 93 species on the islands, 70 (75.3%) of which are introduced. The species records are annotated with emphasis on the geographic origin of each taxon. In addition, the study has led to the molecular reevaluation of the genus Racospermyces, indicating that it is synonymous with Endoraecium, and six new combinations are proposed for the species previously placed in Racospermyces. The high number of introduced species in Hawaii coupled with the paucity of native species when compared to other global regions is discussed.  相似文献   

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